PROJECT SUMMARY/ABSTRACT This research will evaluate levels of association (within and between) and potential moderators (i.e., joint motives and sex differences) of the relationship between physical activity (PA) and alcohol consumption among young adult drinkers. Numerous studies have shown that PA and drinking are positively associated in young adults. Despite this, PA is currently used in interventions to reduce drinking and is promoted as a healthy alternative to drinking. This has critical public health ramifications because a lack of understanding how, why, and for whom these behaviors are positively correlated, at best, weakens the palliative effects of exercise interventions for drinking and, at worst, may be iatrogenic for some individuals. This research will provide clear answers for how, why, and for whom alcohol and PA are positively correlated and will facilitate in the development of innovative prevention strategies by offering personalized feedback based on individual profiles of associations between PA and drinking. Based on our previous work, which indicates that the PA/alcohol association may vary based on self-regulation, and a conceptually integrated, neurobiologically- based framework, we developed and pilot-tested a measure to target joint motives for PA and drinking. We propose that there are two general processes that determine the sequencing of the association between PA and drinking. Alcohol and exercise both engage two forebrain circuits that are critical for effective self- regulation, namely, the reward and the stress systems. The PA?drinking path is expected to reflect reward system activation and be indicative of facets of impulsivity (i.e., work hard, play hard, celebration motives). The drinking?PA path is expected to represent stress system deactivation, where PA serves as a means of reducing negative emotional or physical consequences related to drinking (i.e., guilt, body image motives). In evaluating this framework, we will investigate associations between PA and drinking at daily and weekly levels using an objective measure of PA. We will further examine sex and joint motives associated with the link between alcohol and PA (e.g., work hard, play hard, celebration, body image, guilt), as moderators of these associations and trait-level variables supported in previous studies (e.g., impulsivity, anxiety sensitivity, and BIS/BAS). We will recruit 250 college students from two campuses who report drinking at least once per week. Participants will report daily drinking over 21 days. PA will be assessed continuously using Actical accelerometers. Overall, we anticipate positive associations between PA and drinking and that the temporal sequences of PA and drinking will be influenced by joint drinking and PA motives. Sex differences are expected such that the endorsement of body image and guilt concerns will be more evident and influential among women and work hard, play hard and celebration motives will be more evident and influential for men.